Grease removal apparatus, systems and methods

ABSTRACT

A filter assembly includes a filter pad comprising fibers including natural, synthetic and/or hybrid fibers. A stabilizer frame formed of a non-metallic material may be imbedded in the filter pad. The stabilizer frame may be configured to provide support to the filter pad to maintain the filter pad in a generally flat configuration. In accordance with a particular embodiment, the filter pad may be comprised of at least first and second fibrous mats that are coupled together. In this embodiment, the stabilizer frame may be disposed between and coupled with the first and second fibrous mats.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/614,639 filed Sep. 13, 2012 and entitled “Grease Removal Apparatus,Systems and Methods”, which is a continuation of U.S. application Ser.No. 12/430,650 filed Apr. 27, 2009 and entitled “Grease RemovalApparatus, Systems and Methods” and claims the benefit of U.S.Provisional Application No. 61/099,699, entitled “Disposable GreaseFilter Apparatus and Method,” and filed on Sep. 24, 2008, each of whichis hereby incorporated by reference.

TECHNICAL FIELD

The teachings of the present disclosure relate to the field of exhaustfiltration in ventilation systems and more particularly, to greaseremoval apparatus, systems and methods.

BACKGROUND

In kitchens, the grease filters and/or grease removal devices areusually installed in exhaust hoods above various types of cookingequipment including deep-fat fryers, grills, griddles and ovens whereexcess heat and flame can occur. In applications using existing wool orfiber-based filters (see e.g., U.S. Pat. No. 6,293,983) problems may beencountered due to excessive heat or flame. Unless stainless steel heatshields are placed in front of the wool filters, there is thepossibility that concentrations of heat (e.g., from exhaust of thecooking equipment) may degrade the wool fibers and cause a hole to formin the filter. Similarly, flames may make holes in the filter if theycome in direct contact with the filter which can happen above griddlesand grills with a grease flare-up. This is a major draw-back as a holein the filter renders it ineffective and requires that the filter bereplaced.

When selecting the thickness of a wool filter, there is a tradeoffbetween airflow and grease collection. A thin filter will allowsufficient airflow but will not have a large capacity to collect andstore grease. A thicker filter will allow for greater grease collectionbut reduce airflow. Existing filters of a thickness selected to allowsufficient airflow may not have a large capacity to catch and storegrease. This renders the wool filter expensive to use as it needs to bechanged very frequently, and it is also operationally inconvenient tochange on a regular basis.

Additionally, existing wool filters often require a separate supportframe and frame cover made of metal, which is both costly, heavy for theoperator to use and susceptible to damage, often requiring costlyreplacement. This assembly, and often along with an optional heat shieldmeans the current wool-based system is not only expensive to make butmore significantly it can be difficult for the user to operate. As aresult, operational use has been limited in the marketplace. There isroom for simplification and improvement of this assembly.

The following narrative is provided to give background related to thepurpose, theory and operation of kitchen exhaust hoods.

Kitchen Exhaust Hoods

Commercial and institutional cooking establishments typically employexhaust removal systems to provide ventilation of the workspace, thussupporting the kitchen operation with the removal of heat, grease ladenvapor, smoke, contaminants, and cooking by-product. The primary deviceutilized in the exhaust system for the purpose of capturing the plumeproduced by the cooking appliances, containing fire, and reducing thecontaminants entering the exhaust system is the exhaust hood.

The heating of cooking appliances generally results in a natural upwarddraft of air, which rises from the cooking battery. At the point wherefood is being heated and cooked, the updraft or plume, also known aseffluent, becomes entrained into the air stream rising from the cookingsurface. This by-product will be produced at varying rates based on thesurface temperature of the cooking appliances, and the type of foodsbeing prepared. With cooking processes ranging from low to hightemperatures, and vast differences in the grease content of the foodsbeing prepared, the need exists to provide adequate ventilation of theworkspace, contaminant removal, and fire prevention based on theseverity of the cooking operation.

Non-Grease Versus Grease Type Hoods

Two basic types of hoods are commonly utilized for ventilation purposeswithin commercial and institutional kitchen facilities, with the mainfactor of their division being whether they are designed to ventilategrease-laden vapor or simply heat and vapor. These are divided into type1, (commonly referred to as class 1), constructed and designed for theventing of grease laden vapor, and type 2, (or class 2), for the ventingof heat, vapor, and odor only.

Since the teachings of the present disclosure includes to the capture ofgrease particulates from grease laden vapor, further discussion willfocus primarily upon Class 1 hoods.

Class 1 Exhaust Hoods

Cooking applications which produce grease-laden vapor typically requirethe use of class 1 hoods, which will be divided into two main groups;listed exhaust hoods, and unlisted hoods.

Listed exhaust hoods have been tested for performance by a third partyListing Authority, such as Intertek/ETL or Underwriters Laboratories,for their performance in capturing smoke and vapor at varyingtemperatures, ability to withstand fire conditions, and electricalcomponents survivability in the application.

Grease Removal Devices

Listed and unlisted exhaust hoods, which are used in cookingapplications, will include grease removal devices to reduce the greasevolume of the exhaust air stream prior to the exhaust air entering theexhaust duct. Grease buildup in the exhaust ductwork is considered afire hazard since the deposited by-product remains flammable. With theaccelerated air velocities within the exhaust ductwork induced by theblower, potential risks escalate with the buildup of flammablebyproduct. Failure to remove this byproduct at the source of the greaseremoval device within the hood may result in migration of the flammableload throughout the exhaust duct system.

Grease removal apparatus and systems are normally located within theexhaust hood, and may be either removable for cleaning, or may be afixed component within the exhaust hood for automatic wash down, such asa water wash type hood. Removable type filters are normally arrangedwithin a filter rack, are located just below the exhaust duct collar forthe hood, and typically have a metal grease collection container, whichdoes not typically exceed one gallon.

Baffle Filters

Most common filter hoods today utilize baffle type filters, whichoperate based upon the principle of centrifugal grease extraction. Thesefilters are configured with a series of overlapping baffles, which forcethe grease laden exhaust air to make several changes in direction withinthe grease filter. The grease is dismissed from the air stream bycentrifugal force, held within the filter interior, and accumulation ofthe grease aerosol particles which begin to liquefy continuously drainfrom the filter to a grease drip tray, or trough, and then drain into ametal container which does not typically exceed one gallon.

Baffle filters operate with among the lowest resistance offered by anygrease removal device, which may be between 0.50″ and 0.75″ staticpressure, and the average air velocity at the face of the filter may bebetween 150 feet per minute, and 400 feet per minute, both dependingupon the hood airflow in volume.

Baffle filters are listed to Underwriters Laboratories (“UL”) Standard1046, which tests their ability to perform in the application, and infire conditions. However, UL Standard 1046 does not adequately addressthe effectiveness of the baffle to actually remove grease from the airflow and prevent it from entering the exhaust duct. As a result, mostbaffles are very poor at removing grease from the airflow.

Grease in the ducting constitutes a major fire hazard as duct fires area constant concern in commercial kitchen exhaust systems.

SUMMARY

The teachings of the present disclosure are directed to grease removalapparatus, systems and methods. In accordance with a particularembodiment, the present disclosure provides for a filter assembly thatincludes a filter pad comprising fibers including natural, syntheticand/or hybrid fibers. A stabilizer frame may be imbedded in the filterpad. In a particular embodiment, the stabilizer frame may be formed of anonmetallic material. The stabilizer frame is configured to providesupport to the filter pad to maintain the filter pad in a generally flatconfiguration. In accordance with a particular embodiment, the filterpad may be comprised of at least first and second fibrous mats beingcoupled together, and the stabilizer is disposed between and coupledwith the first and second fibrous mats.

In accordance with an alternative embodiment of the present disclosure,the filter pad may be formed from a single fibrous mat that is coupledwith a stabilizer. In accordance with this embodiment, each of fouredges of the mat are lapped over respective edges of the stabilizerframe.

In accordance with yet another embodiment of the present disclosure, theblend of fibers may include synthetic fibers and/or viscose fibers. Insome embodiments, at least a portion of the fibers may be treated with asolution that is fire resistant or fire retardant.

A technical advantage of particular embodiments of the presentdisclosure includes a filter assembly that is effective at removing orreducing grease particulates from grease laden air. Accordingly, bafflefilters may remain cleaner for a longer period of time, thereby being aneven more effective fire barrier since the fuel source (e.g., greaseparticulates) has been decreased from the airflow prior to reaching anybaffle filters and/or ductwork.

Another technical advantage of particular embodiments of the presentdisclosure includes a filter assembly that distributes flame more evenlyacross a baffle filter, when the filter assembly is located “upstream”from a baffle filter. Accordingly, baffle filters are protected fromfire and damage, perform better, and remain cleaner for a longer periodof time.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following descriptions, takenin conjunction with the accompanying drawings, in which:

FIG. 1 illustrates a filter assembly, in accordance with a particularembodiment of the present disclosure, installed within a vent hood;

FIG. 2 illustrates a disposable grease removal device, in accordancewith a particular embodiment of the present disclosure;

FIG. 3 illustrates a stabilizer that may be a part of the grease removaldevice of FIG. 2, in accordance with a particular embodiment of thepresent disclosure;

FIG. 4 illustrates an alternative embodiment disposable grease removaldevice; and

FIG. 5 illustrates a cross-section of yet another alternative embodimentdisposable grease removal device.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure is directed to grease removal apparatus, systemsand methods. A particular embodiment of the present disclosure includesa filter assembly that may be referred to herein as a Disposable GreaseRemoval Device (“DGRD”), and may be used in, for example, kitchenexhaust systems. In particular embodiments, the DGRD may be formed ofmaterials such that it is generally “self-supporting”, meaning that itdoes not require metal filter support frames, frame covers or heatshields. The DGRD can be formed in a variety of ways using a variety ofmaterials that may result in a DGRD that is either reusable ordisposable. In such embodiments, the DGRD can be easily mounted in theexhaust hoods by simply sliding it into place on brackets or some othersimilar fastening or support system within the exhaust hood.

FIGS. 1-3 illustrate a particular embodiment DGRD 30, in more detail.DGRD 30 is installed within a vent hood 32. Vent hood 32 is configuredand positioned such that air leaving a cooking area will pass throughDGRD 30 before being exposed to (i) a baffle filter (not shown inFIG. 1) that may be positioned behind DGRD 30; and/or (ii) ductworkassociated with vent hood 32 that is configured to remove the air fromthe cooking area (with or without an associated exhaust fan(s)). Venthood 32 includes top and bottom filter clips 34 and 36, respectively,and side clips 38 that collectively secure a plurality of DGRDs 30 inplace, and allow for simplified removal and/or replacement of DGRDs 30.A plurality of direction arrows 40 are provided in FIG. 1 to illustratethe direction of air flow.

The DGRD 30 includes two primary components, either or both of which maybe formed from materials that allow for disposal of the DGRD after asingle use: 1) a filter pad 42 that may be referred to herein as agrease collector pad, and 2) an internal stabilizer frame 44.

The grease collector pad 42 is one of the primary mechanisms that willcapture and remove the grease particulates from the airflow. The fiberswhich make up the grease collector pad 42 are capable of collecting andholding grease particulates from the air that travels through the greasecollector pad 42. In particular embodiments, the grease collector pad 42may be formed principally from a mixture of flame resistant viscosefibers and wool fibers that are woven together, and bonded together witha bonding emulsion that may contain additional additives such as fireretardant, fire suppressant, anti-microbial, anti-bacterial, color dyes,etc.

The internal stabilizer frame 44 is designed to add structure andrigidity to the grease removal device. In the embodiment of FIG. 3, theinternal stabilizer frame 44 has four sides 46 (top 46 a, bottom 46 b,left 46 c and right 46 d), vertical support 48 a, and horizontal support48 b. In a particular embodiment, supports 48 a and 48 b may beapproximately ¾″ wide and approximately 0.125″ thick. In anotherembodiment, the internal stabilizer frame 44 may also be made ofpractically any non-metallic material, for example a natural,bio-degradable material that is lightweight and flame-resistant. Theinternal stabilizer frame 44 could be made of practically any materialthat will pass any required regulatory codes. The stabilizer frame mayalso include any number of horizontal, vertical and/or diagonal supportsof practically any size or configuration. Functionally, it is beneficialfor the internal stabilizer frame 44 to add shape and structure to theDGRD with relatively little added weight and/or very little added staticpressure.

The DGRD of FIG. 2 is generally formed by inserting the internalstabilizer frame 44 within or between two grease collector pads 42. In aparticular embodiment, the internal stabilizer frame 44 may be coatedwith glue on both sides, which allows the internal stabilizer frame 44and the grease collector pad 42 to be merged together into a singleDGRD.

The DGRD can be manufactured using a variety of processes andalternative materials. Included herein is a description of variousdetails related to how the two primary components of the DGRD can beproduced. The two primary components noted above are the greasecollector pad 42 and the internal stabilizer frame 44.

FIG. 4 illustrates a DGRD 30 a, in accordance with another embodiment ofthe present disclosure. DGRD 30 a includes a grease collector pad 42 aand an internal stabilizer frame 44 a, that are similar to greasecollector pad 42 and internal stabilizer frame 44 of FIG. 2. However,the method for manufacturing DGRD 30 a would be slightly different. DGRD30 a is formed using a single grease collector pad 42 a that is bigenough to overlap internal stabilizer frame 44. Thus, at each edge ofthe internal stabilizer 44 a, the grease collector pad is lapped overthe internal stabilizer frame 44 a. An optional diagonal support 46 e isalso included on the internal stabilizer frame.

FIG. 5 illustrates yet another DGRD 30 b, in accordance with yet anotherembodiment of the present disclosure. DGRD 30 b includes a single greasecollector pad 42 b. An internal stabilizer frame 44 b is embedded withingrease collector pad 42 b, which is simply woven around internalstabilizer frame 44 b to manufacture DGRD 30 b.

Grease Collector Pad

The grease collector pads of this disclosure can be manufactured usingone or more (e.g., a blend) of various fibers. For example, at leastthree different types of fibers may be used: (i) natural fibers, (ii)synthetic fibers, and/or (iii) hybrid fibers. For the purposes of thisdisclosure, “natural” fibers generally refers to fibers that are derivedfrom nature and include wool (e.g., sheep's wool or any other animalhair), cotton, linen, hemp, manila, flax, plant fibers, jute sisal, etc.For the purposes of this disclosure, “synthetic” fibers generally refersto fibers that are man-made, and include nylon, polyester, acrylic,polypropylene, polyethylene, polystyrene, flame resistant modifiedacrylic, etc. For the purposes of this disclosure, “hybrid” fibersgenerally refers to fibers that are derived from nature but materiallymodified by man, and include viscose, rayon, PLA, PLA flame resistantpolymers, biodegradable flame resistant polymers, flame resistant rayon,synthetic fiber derived from a natural source, fibers that are derivedfrom corn starch, etc. Most of the above referenced fibers may also beused in a flame resistant form in which a flame resistant additive isimpregnated into the fibers.

One particular embodiment of the present disclosure is a mixture of woolfibers and flame resistant viscose fibers. The blended fibers may besprayed with a bonding emulsion that may be selected such that it isbiodegradable. In various embodiments, the bonding emulsion may containfire-resistant, fire-retardant and/or fire-suppressant ingredients,antimicrobial agents and a color dye mixed with it in any combination.

The grease collector pads may also be made using wool and flameresistant viscose blended in any ratio. For example, the ratio could beas much as 95% wool and 5% flame resistant viscose or as much as 95%flame resistant viscose and 5% wool. In general, practically any ratioof the blended flame resistant viscose and wool may be employed, withinthe teachings of the present disclosure. In other embodiments, the ratiocould also be 100% flame resistant viscose or 100% wool fibers.

For example, the following describes blends that may be used inaccordance with particular embodiments of the present disclosure:

-   -   50% wool and 50% 8-9 denier flame resistant viscose bonded with        biodegradable flame resistant treated acrylic bonding emulsion        (for purposes of this specification, “denier” is a unit of        measurement of linear density of textile fiber mass, calculated        as one gram per nine-thousand meters).    -   100% 8-9 denier flame resistant viscose bonded with        biodegradable flame resistant treated acrylic bonding emulsion.    -   50% wool/25% 8-9 denier flame resistant viscose/25% 2 denier        flame resistant viscose bonded with biodegradable flame        resistant treated acrylic bonding emulsion.        In other embodiments, the viscose and/or flame resistant viscose        may be provided within a range of 2-9 denier, or within a        narrower range of 4-8 denier. In particular embodiments, it may        be provided at 5 denier.

In addition, the wool or flame resistant viscose could be blended withother fibers that are natural, synthetic and/or hybrid fibers, which canimpart flame resistant or structural properties to the resultantapparatus. This could include rayon, flame resistant rayon, flameresistant modified acrylic, PLA flame resistant polymers, biodegradableflame resistant polymers, plant fibers or flame resistant natural fibersderived from plant fibers i.e. jute, flax, hemp, sisal, cotton, manila.In accordance with another embodiment, wool and viscose may be blendedin any percentage then treated with a fire retardant that would impartfire retardant properties to the wool and viscose blend. This could alsobe a blend of any natural or synthetic fibers blended in any percentagewhich could be treated with a flame resistant compound to make theoverall blend flame resistant.

In accordance with a particular embodiment, the wool/flame resistantviscose may be treated with flame retardant and/or flame suppressantcompounds to improve the heat and flame resistance of the resulting pad.Alternatively, the process may omit flame resistant and/or flamesuppressant treatment as it is determined by testing of the variousblends to heat and flame for a particular application.

The flame resistant viscose fiber is relatively heat and flame resistantand will only degrade under extreme conditions of heat and flame. Forthis reason, flame resistant viscose fibers are used extensively inclothing for firemen, welders, military and others that are exposed tosevere heat and/or flame. This may be important given that the DGRD isoften installed above deep-fat fryers, grills, griddles and ovens in thekitchen where excess heat and flame can occur. Flame resistant viscosefibers being blended into the grease collector pad 42 may significantlyimprove heat and flame resistance properties of the DGRD.

While wool is naturally flame resistant, in an open structure the woolfibers may be exposed to higher concentrations of oxygen in certainconditions. For this reason, a flame retardant and/or fire suppressantmay be applied in accordance with particular embodiments. However, withthe flame resistant viscose or other similar fiber it may not berequired, or may be required in smaller concentration, depending on theplanned application.

Flame resistant viscose fibers capture grease and contaminants fromgrease laden vapor. Therefore, when used in combination with wool fibersthere is very similar grease capturing ability, but, with the addedbenefit of more robust performance against heat and flame.

In accordance with particular embodiments of this disclosure, thebonding emulsion may be used to provide a way to apply thefire-retardant/suppressant compounds or any other additives such ascolor dyes, anti-bacterial, antimicrobials, etc. The bonding emulsionmay also be used to bond the blended fibers together in the desiredshape. The bonding emulsion may be designed so that it will break downover time when the DGRD is disposed of after use (i.e., isbiodegradable).

Wool fibers are bio-degradable and the flame resistant viscose fibersmay be made from wood pulp and/or in such a way that it is 100%bio-degradable. Hence, the resulting grease collector pad 42 using thisblend of material and bonding emulsion may be fully biodegradable and assuch can be easily disposed of without effecting the environment.

The bonding emulsion, in particular embodiments, is made frombiodegradable components comprising a blend of acrylic co-polymers. Itmay also be made with other natural occurring and biodegradable binderssuch as starch and protein adhesives. Synthetic bonding components whichhave biodegradable properties including, but not limited to, PLA(Polylactic acid) may also be used. Ultra-sound and/or Hydrogen-bondingmay also be a used as a bonding method.

In accordance with a particular embodiment, the grease collector pad 42may be formed from a 50% blend of fire-resistant 5-denier×64 mm flameresistant viscose and 50% of fibers comprised of 100% lamb's wool. Thelamb's wool may be clean, scoured 28 micron wool in 1 to 3 inch lengths.A single grease collector pad 42 in this embodiment may have a weight ofapproximately 100 grams per square meter and a loft of approximately 8mm.

Following is a discussion of various manufacturing processes that couldbe used to produce the grease collector pad 42, in accordance withparticular embodiments of the present disclosure.

The scoured wool may be “opened” to enable easier processing. The woolmay then be blended with the flame resistant viscose or similar fiber asa pre-blend, and transferred to be put through a non-woven cardingmachine which further opens and generally aligns the blended fibers. Thecard may be used to make the fiber blend into a fiber web which may thenbe layered using a cross lapping machine into a blended fiber wadding.If a grid or mesh was to be introduced it would feed into the blend atthe cross lapper of a roll. The lapping and carding may be used toensure the fibers are aligned correctly so that when the fiber waddingis sprayed with binder that the final grease collector pad 42 will havesufficient, predetermined minimum loft.

The wool/flame resistant viscose blend may also be needle punched into anon-woven blanket. Other non-woven process such as needling,thermo-bonding, ultra-sound, air laid, spunbond or other non woventechnology may be used to form the wadding/blanket.

At this stage the bonding emulsion may be applied by spraying the topand the bottom of the wadding with the spray mix. The emulsion isapplied in a diluted form to allow penetration through the wadding.Vacuum is applied below the wadding to further assist the penetration ofthe fiber with the bonding emulsion. The bonding emulsion may be used toapply the other additives such as fire retardants, fire suppressants,anti-microbial agents, anti-bacterial agents, color dyes, etc. so thesolution should be applied relatively evenly and in the correct,predetermined proportions.

As the thickness of the wadding and grams per square meter can vary, theamount of bonding emulsion will also vary, so that it matches what isdesired to sufficiently bond the grease collector pad 42 and impart thedesired physical and fire resistant properties.

The spray bonded wadding may then be passed through an oven at over 280F to drive off the water and cure the bonding resins. The resultantwadding may then be rolled into rolls and allowed 24 hours to cure andthe binder to be fully effective. During this time the wool absorbsmoisture from the atmosphere. The resultant wadding may then be madeinto rolls cut at specific widths and lengths.

The grease collector pad 42 media could be made as a flat sheet or itcould be folded into pleats. The use of pleats may provide additionalcapture capacity due to the pleats resulting in more surface area forcapacity available within the same area.

Internal Stabilizer Frame

One function of the internal stabilizer frame is to provide dimensionalstructure and rigidity to the DGRD. The internal stabilizer frame, in aparticular embodiment, may be made from fire-resistant fiberboard (e.g.,that is 0.125″ thick) and can be either die-cut or cut into individualstrips and assembled into the required shape, and may include anycombination of diagonal, vertical or horizontal support members.Alternative materials may also be non-woven 100% flame resistant viscosefibers which have been needle punched so that it has the consistency ofthick cardboard and as such can be used to make the internal stabilizerframe. The flame resistant viscose is flame resistant. The non-wovenflame resistant viscose could then be cut into strips and assembled ordie-cut into the shape required for each internal stabilizer frame withany combination of vertical, horizontal or diagonal support members.

Other materials that could be used to make the internal stabilizer frameinclude flame resistant treated jute or Sisal fiber or flame resistanttreated plastics and polymers.

Assembly of the DGRD

The DGRD is formed when the grease collector pad and the internalstabilizer frame are merged together to create a single unit. In aparticular embodiment the assembly process includes inserting theinternal stabilizer frame between two grease collector pads. Inparticular embodiments, both sides of the internal stabilizer frame maybe coated with a glue which results in the components being held firmlytogether when pressure is applied to the unit to compress the assembly.In the embodiment described above, the DGRD may weigh approximately 250grams per square meter (“gsm”) with a loft of approximately 22-25 mm. Inother various embodiments, the DGRD can vary in weight from 50 gsm to750 gsm. The weight used is a dry mass weight based on the productionweight of the grease collector pad when they come off of the productionline. The resultant grease collector pad assembly may have a dry loft of5 mm to 55 mm.

Alternative Embodiments

The DGRD may be made in other shapes and sizes using the same primaryingredients as the embodiments described above. For example, thefollowing is an alternative method of design for the DGRD that may usesome or all of the same materials but assembles them with the internalstabilizer frame disposed upon the exterior of the fiber media.

The internal stabilizer frame cartridge or frame panel may be made byusing a fire resistant stiff material and die cutting it into a framewith diagonal and/or horizontal support members. The fiber mediacomprising the wool/flame resistant viscose blanket may be bonded to theinside perimeter of the external frame using glue providing a continuousand positive seal.

The fiber media may be installed as a flat sheet in the enclosure frameor it could be folded into pleats. The pleats may need to be supportedwith a grid made from any natural or synthetic material which exhibitsfire resistant properties. It may also be expanded metal but this hasthe disadvantage of not being biodegradable. Natural grids or meshescould include flame resistant viscose, flame resistant treated jute orSisal fiber or flame resistant treated plastics and polymers. The pleatsper linear foot would vary depending on the thickness of the fibermedia. Alternatively the fiber media could be a flat sheet with nopleats.

Another method to add support to the fiber media would be to include amesh or grid in the non woven manufacture. The grid or mesh may beinserted in the middle of the wool/flame resistant viscose blend duringmanufacture. This would mean the fiber blend itself would offer flameresistance and heat protection to any grid or mesh used. So it'spossible the grid or mesh used may not need to be flame resistant. Thedie cut material could be non-woven flame resistant viscose as this hasexcellent strength and excellent flame and heat resistance. It is alsobiodegradable. However the die cut material may also be formed from anynatural or synthetic material particularly if they have biodegradabilityand flame resistant properties. Even flame resistant treated cardboardcould possibly be used in the manufacture of the die cut support.

The structure and support need not only be die cut. It could be weldedsupports, or supports fixed to the fiber media directly or injectionmolded plastic or extruded plastic profiles or any combination of theseconstruction methods. The fiber media could also be made to be morerigid during the manufacturing process by varying the composition of thefibers and the density, varying the non woven by needling or other nonwoven process or the application and type of bonding emulsion andvarying the curing temperature or any combination of these. This couldenable the fiber media to be produced into a pleated pad without theneed for additional support with an expanded mesh or grid.

The die-cut external internal stabilizer frame may be made from nonwoven 100% flame resistant viscose which has been needle punched so thatit has the consistency of thick cardboard and as such can be used tomake the support frame. The flame resistant viscose is flame resistant.The non-woven flame resistant viscose is die cut into the shape requiredfor each grease collector pad with diagonal and horizontal supportmembers. To complete the cartridge up to 2 die cut frames may berequired. Effectively a front and back side of the internal stabilizerframe. The wool/flame resistant viscose media may then be cut into thesize required to fit the support frame. If the media is to be pleated itwill have to be cut to a larger size to allow for the additionalrequirement due to the pleats. This will vary depending on the number ofpleats per linear meter and the depth of the internal stabilizer frame.At this stage, if an extra supporting grid or mesh is required it can beadhered to the fiber media by some type of flame resistant adhesive.Alternatively it could be stitched or sewn in place with flame resistantthread. The die cut support frames are then assembled using flameresistant adhesive ready for the fiber media to be added. The fibermedia pack comprising the wool/flame resistant viscose, pleated or not(e.g., flat sheet) which is then bonded with a flame resistant glue tothe inside perimeter of the enclosure frame, providing a continuous andpositive seal.

The resulting DGRD cassette is then quality inspected and is ready forinstallation and use. The DGRD may be supplied as panels and cassetteswhich are ready to install.

The DGRD may then be installed in hoods and exhaust units in kitchensand food preparation areas. The grease collector pad will effectivelycapture the grease and other contaminants. In some embodiments, thehoods or exhaust hoods will need to have a simple bracket (e.g., Zbracket) or similar installed to support the DGRD.

The cassettes are then placed in the brackets in the hoods in front ofthe flame baffles. A tool with an extension arm may be used to mount orreplace DGRD. Sufficient DGRD's should be installed to cover the hoodaperture and the DGRD's may be butted up against each other to form aneffective seal.

When one or all of the DGRD's is full of grease, it's a simple matter toremove them and install a replacement.

DGRD Performance

In particular embodiments, the DGRD may have improved performancerelative to existing filter systems, in collecting grease in variousparticulate sizes as per testing that may be done using the ASTM F-2519Astandard.

In such embodiments, the DGRD may have larger grease capacity than otherfiber filters available and even with the higher grease holding capacitythe resulting static pressure increase of the DGRD may be less thanother fiber-based filters. This results in kitchen hoods being able torun efficiently without the need to add larger motors. When the DGRD isfull it may simply be replaced with a new DGRD and the soiled pad can bedisposed of in an environmentally friendly manner. The DGRD may be madein such a way that it can be fully bio-degradable and may breakdown 100%in a landfill in less than 12 months.

Mounting Brackets

Mounting brackets may also be provided as part of the DGRD. They can beformed of practically any material that will support the weight of theDGRD and hold the DGRD firmly in place within the exhaust hood. Inaccordance with a particular embodiment of the present disclosure, tomeet various codes and regulations governing exhaust hoods, the mountingbrackets may be comprised of Stainless Steel and/or anothernon-combustible material. The mounting brackets may be designed topractically any shape to hold the DGRD in place and maintain asufficient seal within the hood aperture. In particular embodiments ofthe present disclosure, the mounting brackets may be made of StainlessSteel and formed into the shape of “Z” or “U” to hold the DGRD in place,and allow for simplified removal and/or replacement of DGRDs.

Installation/Removal Tool

An installation/removal tool may also be provided as part of the DGRDSystem. The installation/removal tool may be used to allow an operatorto effectively reach the DGRD when installed within the exhaust hood,without having to climb onto the cooking equipment. Theinstallation/removal tool may be comprised of lightweight aluminum orplastic as the weight of the DGRD does not require a particularly“heavy-duty” material. However, practically any material can be used tomake the installation/removal tool that is strong enough to hold theDGRD. The end of the mounting tool includes a plurality of prongs whichare used to slightly pierce the front of the DGRD to grab the internalstabilizer frame 44 for lifting and inserting the DGRD into the mountingbrackets for installation. For DGRD removal, the prongs on the end ofthe installation/removal tool are used to pierce completely throughgrease collector pad 42 and simply lift and remove from the mountingbrackets.

The present disclosure is generally directed to a removable and/ordisposable grease removal device that is placed between the cookingsurface and the baffle filters described herein, to capture greaseparticulates from grease laden vapors prior to entry into, or “upstream”from the baffle filters described herein. It should be noted thatexisting grease removal devices are typically located “downstream” ofbaffle filters.

Although an embodiment of the disclosure has been described usingspecific terms, such description is for illustrative purposes only. Thewords used are words of description rather than of limitation. It is tobe understood that changes in variations may be made by those ofordinary skill in the art without departing from the spirit and scope ofthe present disclosure, which is set forth in the following claims.Therefore, the spirit and scope of the appended claims should not belimited to the description of the embodiments disclosed therein.

The invention claimed is:
 1. A filter assembly, comprising: a filter padcomprising a combination of wool fibers and viscose fibers and having athickness and configuration sufficient to allow airflow therethrough andto absorb grease particulates dispersed in the air passing therethrough;and wherein the viscose fibers comprise approximately 50% to 95% of thefilter pad; a stabilizer frame comprising a first support, a secondsupport opposite to the first support, and a plurality of supportsextending between the first support and the second support; and whereinthe stabilizer frame is configured to provide support to the filter padand to allow installation of the filter pad within a ventilation hood.2. The filter assembly of claim 1, wherein the filter pad is comprisedof at least first and second fibrous mats being coupled together, andthe stabilizer frame is disposed between and coupled with the first andsecond fibrous mats.
 3. The filter assembly of claim 1, wherein thefilter pad is formed from a single fibrous mat that is coupled with thestabilizer frame, and wherein each of four edges of the mat are lappedover respective edges of the stabilizer frame.
 4. The filter assembly ofclaim 1, wherein the viscose fibers comprise 8-9 denier flame resistantviscose bonded with biodegradable flame resistant treated acrylicbonding emulsion.
 5. The filter assembly of claim 1, wherein the viscosefibers are within the range of 4-8 denier.
 6. The filter assembly ofclaim 1, wherein at least a portion of the fibers are treated with asolution that is fire resistant or fire retardant.
 7. The filterassembly of claim 1, wherein the filter assembly has a total dry weightapproximately between 50 and 750 grams per square meter.
 8. The filterassembly of claim 1, wherein the filter assembly has a dry loft ofapproximately between 5 mm and 55 mm.
 9. A method of manufacture,comprising: combining wool fibers and viscose fibers to form a filterpad; wherein the viscose fibers comprise approximately 50% to 95% of thefilter pad; coupling the filter pad with a stabilizer frame; wherein thestabilizer frame is formed to have a first support, a second supportopposite to the first support, and a plurality of supports extendingbetween the first support and the second support; and wherein thestabilizer frame is configured to provide support to the filter pad andto allow installation of the filter pad within a ventilation hood. 10.The method of claim 9, wherein the filter pad is comprised of at leastfirst and second fibrous mats being coupled together, and the stabilizerframe is disposed between and coupled with the first and second fibrousmats.
 11. The method of claim 9, wherein the filter pad is formed from asingle fibrous mat that is coupled with the stabilizer frame, andwherein each of four edges of the mat are lapped over respective edgesof the stabilizer frame.
 12. The method of claim 9, wherein the woolfibers comprise approximately 50% of the filter pad.
 13. The method ofclaim 9, wherein the viscose fibers comprise 8-9 denier flame resistantviscose bonded with biodegradable flame resistant treated acrylicbonding emulsion.
 14. The method of claim 9, wherein at least a portionof the fibers are treated with a solution that is fire resistant or fireretardant.
 15. The filter assembly of claim 1, wherein the filter padcomprises a pleated configuration.
 16. The filter assembly of claim 1,wherein the stabilizer frame is configured to provide support to thefilter pad to maintain the filter pad in a generally flat configuration.17. The filter assembly of claim 1, wherein the filter pad comprises abonding emulsion applied to the fibers.
 18. The method of claim 9,wherein the filter pad is formed to have a pleated configuration. 19.The method of claim 9, wherein the stabilizer frame is formed to providesupport to the filter pad to maintain the filter pad in a generally flatconfiguration.
 20. The method of claim 9, further comprising applying abonding emulsion to the fibers.